simple question about normal maps in maya

n88tr

So I've been watching a lot of youtube videos [how else am I gonna do it lol?] about Maya normal map creation, baking I think it's called.

I'm cool with the settings of baking, but I have a question.

Say I have my high poly object and my low object. How close in size do they need to be to each other?

Without opening Maya and just thinking about how I would do this operation, I would make the low first, call it good then detail it up and up to make the high. Meaning the existing low would be transformed with polies to become the high. Is this normally how you'd do it?

Or would you create a brand new model and make it try to look like the low in it's basic shape and then just add details to it to make it become the high? I could go either way but I just want to know what would work best.

PS my first normal-mapped object I plan to make is a sword. I have 3 designs lined up, pretty simple I hope.

Thank you Polycount.

Bal

In most cases it's easier to make the low once you've finished the high (through retopologoy often), except if you're already sure of the shapes and don't plan on changing them much.

But there's no strict way of doing things, test around until you get a feel for how things work best for you.

EarthQuake

High first, as features and shapes often change when you get to the point of a finished highpoly, doing low first is very restrictive, artistically/aesthetically speaking.

Your low should match your high as much as possible. It shouldn't be smaller, or larger, but as close to the same as possible. A lot of baking errors can arise when your low isn't properly matched to your high.

n88tr

So I make the high first and then what, delete polies to make it the low?

Shogun3d

You will want to create your high poly model first. Ideally this is more efficient because you will need to work in quads for proper model subdivision. Once you complete your high poly model, you can duplicate it and rename the 2nd one as your low poly model. Then simply start optimizing it by removing edges, connecting verts and creating tris to staple in saved tri-count. You can see why you won't want to work from low to high. When Creating Tri's, you potentially cause issues in subdivision, that and you will need to recreate parts of the high poly.

Also, make sure you do some research here on polycount as a ton of your questions can be answered, just like mine were at some point.

http://wiki.polycount.com/NormalMap

Bookmark that as reference when dealing with normal maps, high and low poly models. The wiki has tons of good info in general.

n88tr

Thanks for the link. The things about AO, diffuse, and spec I still don't get at all so for now I'll try to focus on just normals for now.